<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    function Foo() {
      getName = function () {
        console.log(1);
      }
      return this;
    }
    Foo.getName = function () {
      console.log(2);
    }
    Foo.prototype.getName = function () {
      console.log(3);
    }
    var getName = function () {
      console.log(4);
    }
    function getName() {
      console.log(5);
    }
    Foo.getName(); // 2
    getName(); // 4
    Foo().getName(); // 1
    getName();// 1
    new Foo.getName(); // 2
    new Foo().getName(); // 3
    new new Foo().getName(); // 3
  </script>
</body>

</html>